Continuous pair furnace



Dec. 3, 1935. R FENTON 2,023,318

CONTINUOUS PAIR FURNACE Filed April 24, 1933 5 Sheets-Sheet l INVENTOR.

ATTORNEY5 Dec. 3, 1935. V R. M. FENTON CONTINUOUS PAIR FURNACE Filed April 24, 1953 5 SheetsSheet 2 INVENTOR. Kay W2. wzfarz,

v fig ATTORNEY5 Dec. 3, 1935. R M FENT N 2,023,318

CONTINUOUS PAIR FURNACE Filed April 24, 1933 3 Sheets-Sheet 3 INVENTOR.

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BY @01 m ag ATTORNEYS Patented Dec. 3, 1935 v UNITED STATES PATENT OFFICE 16 Claims.

This invention relates, as indicated, to a continuous pair furnace and more Specifically to a furnace adapted for the purpose of conveying in succession a plurality of bars or pairs of bars through a heating chamber preparatory to hot working of the metal by rolling.

It is among the objects of my invention to provide a pair furnace of the continuous type in which the bars carried therethrough will be 19 uniformly heated at a minimum of expense. It is a further object of my invention to provide a furnace of the above defined character in which bars are maintained in a highly heated state up to the time when they are discharged therefrom preparatory to rolling. It is a fur ther object of my invention to provide a furnace of the above defined character with combustion chambers so positioned, arranged and related to the heating chamber to insure maximum efficiency of operation and uniform heating of the work passing through the furnace. Other objects of my invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention, then consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings:---

Figure l is a longitudinal, vertical, part sectional, part elevational view of a pair furnace constructed in accordance with the principles comprising my invention; Figure 2 is a fragmentary, sectional View drawn to a slightly enlarged scale of the discharge end of the furnace illustrated in Figure 1 and showing a slight modification in such construction; Figure 3 is a left end elevational view of the apparatus disclosed I in Figure 2; Figure 4 is a horizontal, transverse W sectional, part elevational view of the furnace illustrated in Figure 1; Figure 5 is a transverse sectional view of the furnace as illustrated in Figure 4 taken on a plane substantially indicated C ings and more especially to Figures 1 and 4, the

furnace comprising my invention of a heating chamber, generally indicated at I, which is substantially rectangular in form and comprising side, top and bottom walls formed of the usual refractory material employed in furnace con- 5 struction. The details of construction of the heating chamber proper will not be gone into in this description for the reason that any suitable type of construction such as has been commonly employed in the prior art may be utilized in the construction of the heating chamber. My invention relates particularly to the means for carrying the bars through the furnace for discharging the same after they have been heated and for effecting circulation of the burning, 15 heating gases through the heating chamber in the manner and for the purposes hereinafter more fully explained.

The work conveying mechanism As most clearly illustrated in Figure 5, the bottom 2 of the heating chamber I is provided with paralleled longitudinally extending inverted T-shaped grooves 3 on the bottom of which may be provided suitable wear-resistant tracks 3a, preferably of some heat-resistant metal. Adjacent opposite ends of the bottom 2 and extending transversely thereof are shafts 4 and 5 the latter of which, as most clearly illustrated in Figure 4, is in driving communication with an electric motor 6 through a suitable speed reduction unit I. The former shaft 4 is carried by movable arms 4' which are engaged by rocker arms 4a on which are suspended counterweights 4b; the counterweights through the arms 4a tend to 3 urge the shaft 4 to the right as viewed in Figure 1 so that all slack in the chain due to wear is automatically taken up. Mounted on the shafts 4 and 5 are paired axially spaced sprockets 8 about which are trained endless chains. The upper runs of the endless chains lie in the inverted T-shaped grooves 3 and the lower runs thereof lie in supporting brackets 9 suspended from the bottom frame of the furnace.

The chains So, as most clearly illustrated in Figure 6, consist of a plurality of articulated links H] and II arranged alternately and interconnected by means of transverse pins l2. Rollers not are mounted on pins 12 in a manner well understood in the art. Alternate links ll of the chain are provided with projections l3 to which are secured-work-carrying blades It which are notched at their ends as at IS. The blades M are secured to the chains 8a in paired relation at longitudinally spaced points with the two blades in each pair laterally aligned so that the pair of bars may be supported on and carried by each pair of blades I4.

The upward projection I6 on the forward edge 9.: the blades l4 engages the bottom edge of the bars which are supported in slightly inclined position on the leaves and rest against the rear projection [1.

Any suitable means may be provided for charging the bars either singly or in pairs to the blades H as they pass around the right hand sprocket 8. If the projections H are of sufiicient length rela tive to the width of the bars, the bars either singly or in pairs may be moved in laterally abutting relation towards the sprocket 8 on a fiat table to be picked up by the blades M as they pass around the right-hand sprocket 8.

As most clearly illustrated in Figure 2, the floor or bottom 2 of the heating chamber at the left discharge end of the furnace slopes downwardly as at l8 and on this sloping portion are provided laterally spaced skid members l9. As the blades l4 pass around the left end sprockets 8, the bars will fall out of the blades onto the skids is to be discharged onto suitable means not shown whereby they are carried or conveyed to the mill for working.

During the normal operation of the furnace, it will be noted that to discharge a single pair or bar from the furnace to work the same, the endless conveyor will be moved for a distance represented by the distance through which the last two blades or' brackets M are spaced as viewed in Figure 1, i. e., the bracket which carries the pair or bar to be discharged will be moved to a position approximately 30 with respect to the horizontal, which will retain the next succeeding bracket or blade [4 in the normal vertical position, so that each pair or bar, until it is discharged, is supported edge-wise in the path of the flame or burning gases within the furnace and, therefore, prevented from scaling or becoming chilled while waiting to be discharged.

The above defined operation and its attendant desirable results is made possible by a proper proportioning between the normal longitudinal space between succesive brackets or blades I4 and the radius of the sprocket 8 at the discharge end of the furnace about which the endless conveyor is trained.

The angular relation of the skids Hi to the direction of movement of the blades or brackets I4 is such that the forward projection I 6 on the blades or brackets l4 move below the work supporting surface of the skids i 9 before the bars or pairs are tilted so as to slide down the skids l9, thereby facilitating the discharge of the pairs or bars and preventing the projection i 6 from interfering with the work bars descent down the skids IS.

The manner in which the brackets or blades I4 disengage the pairs or bars, as above explained, is somewhat more clearly illustrated in Figure 2 in which is shown the position of the supporting blades or brackets I4 in the several positions with relation to the skids i9 and several dotted line positions of the work as it is being discharged.

The combustion chambers The furnace illustrated in the drawings for purposes of description is of the gas-fired type. As most clearly illustrated in Figure 4, the heating chamber I has two combustion chambers associated therewith respectively arranged at opposite sides and at opposite ends of the heating chamber. These combustion chambers, generally indicated at 20 and 2| respectively may be formed by lateral offsets in the side walls of the furnace proper. At the forward ends of these combustion chambers are provided tuyeres 22 and 23 respectively with which burner nozzles 24 and 25 are associated. The burner nozzles 2 5 and 25 are connected in communication with gas supply means and are of any usual design such as has been commonly employed in the prior art for adjustabiy controlling the flow of gas into the combustion chambers.

The combustion chambers 26 and 2%, as illustrated in Figures 4 and 5, are separated from the heating chamber i by means of partial partitions 26 which extend only part way to the roof of the furnace, so that the burning gases from the combustion chamber flow over this partial wall or partition onto, over and around the work carried through the furnace by the blades Hi.

Instead of having two combustion chambers associated with each heating chamber as illustrated in Figures 1 to 5, I may prefer to provide only one combustion. chamber with the heating chamber, as illustrated in Figure 8. Regardless of the number of combustion chambers employed. I may prefer to modify the partition such as 28 between the combustion and heating chambers in the manner illustrated in Figure 8. In this lastnamed figure, the partition 2'! interposed between the combustion and heating chambers adjacent the tuyre 22 is stepped down as at 23 so that the work alongside this portion of the combustion chamber may be heated by radiation from the flame projected into the combustion chamber through the tuyere. After the combustion of the gases has been partially completed, the hot gases are permitted to pass over the partition 2'5 into the heating chamber in the area indicated at 29.

In order to effect a turbulence of this flow of the hot gases, in order to properly divert the same. and to generally insure a more uniform heating of the work passing through the heating chamber, the upper edge of the wall 2? adjacent the overflow area 29 may be provided with a series of longitudinally spaced bafiies arranged with respect to the flow of gas in the manner most clearly illustrated in Figure 8.

In order to further insure the uniform heating of the work on all sides, the lower edge of the wall 21 adjacent the bottom of the furnace is provided with a series of longitudinally spaced, transversely extending apertures 3 through which a portion of the burning gases will project and impinge upon and circulate around 5 the lower edges of the work carried by the blades M. It should also be noted that in order to effect a proper distribution of flow of the burning gases from the combustion chamber to the heating chamber, the combustion chamber may, at its rear end 32, be constricted so as to insure an equal distribution of gas flow over the upper edge of the partition wall.

Flue connections for heating chamber although in addition thereto some means must be provided to insure against heat loss at these open ends and further, to subject the bars in the ends of the furnace, particularly the discharge end, to the direct action of the burning or highly heated gases. This is particularly desirable at the discharge end for the reason that the bars should be kept as highly heated as possible up to the very moment of discharge so that the bars or pairs of bars will not have an opportunity to cool while waiting at the discharge end to be taken from the furnace and worked. It is especially important to insure a proper gas flow to both ends of the furnace so that the maximum amount of heating may take place for a minimum length of furnace structure. Some means also should be provided so that the circulation of the burning gases through the furnace will not have a tendency to entrain cold air from the outside of the furnace through the open ends which would have a tendency to chill the furnace and generally reduce its operating efficiency.

In order to accomplish the foregoing ends, I provide hoods 33 and 34 respectively adjacent the charging and discharging ends of the furnace and which extend outwardly from the furnace in overhanging relation to the openings in the ends of the furnace through which the material is moved. The structure of the hood 34 associated with the discharge end of the furnace is most clearly illustrated in Figure 2 in which such hood is shown substantially arcuate in form and provided with flues 35 and 36. These flues are substantially arcuate in form and are, at their lower forward surfaces, provided with openings 31 which draw off at least a portion of the hot gases and flame from the heating chamber and lead the same to a stack or flue generally indicated at 38.

The hood 33 adjacent the charging end of the furnace is provided with a similar flue 39 which also carries off at least a portion of the hot gases and flame from the heating chamber.

Providing flues in the hoods 33 and 34 causes the hot gases and flame from within the furnace to flow towards the opposite ends thereof for the following advantages: The gas and flame flowing to the hood 34 will pass over the work car ried on the last pair of leaves I4 until the very moment when such leaves are moved into a position to discharge the work onto the skids IS. The bars or pairs are, therefore, maintained at the maximum temperature until the very moment when they are discharged for rolling, The gases and flame towards the charging end to pass out through the flue 39 are effective to preliminarily heat the work which is charged into the furnace so that the entire length of the heating chamber is efliciently utilized so that the maximum amount of stock maybe heated in a minimum length of heating chamber. The gases flowing towards theopposite ends of the heating chamber to be drawn off therefrom by the flues 35 and 39 are effective to produce a gas seal across the open ends of the furnace to prevent cold air from without the furnace being entrained into the heating chamber which would have the efiect of reducing the temperature of the heating chamber and generally reducing the efficiency of operation of the furnace. By providing suitable dampers with each of the flues 35 and 39, the temperature in various portions of the furnace as well as the temperature of the work passing therethrough may be accurately controlled.

Attention is directed to the fact that the hoods such as are generally indicated at 35 and 36 associated with the aprons or arches extending over the openings into the heating chamber in themselves form a substantial portion of such arch or apron, thereby greatly facilitating the construction of this portion of the furnace.

As particularly indicated with regard to the hood 39 it will be noted that such hood, as well as the hoods such as 35 and 36, may have a flue section more or less permanently or fixedly associated therewith so that they may be removed as a unit which also assists in simplifying the construction and repair of the furnace as well as reducing the cost of its manufacture, installation and operation.

By supporting the pairs or bars on edge during their travel through the furnace, it is possible to circulate burning gases more efficiently around the bars than in any form of construction. heretofore employed and this freedom of circulation of the gases around and about the work barsin the furnace decreases the time interval required to effect a proper heating thereof; insures a more uniform heating of the bars and generally increases the efficiency of heat transfer between the gases and the bars and accordingly increasing the efficiency of the furnace as a whole.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated m'eans be employed.

I, therefore, particularly point out and dis-- tinctly claim as my invention:-

1. In a continuous pair furnace, the combin-a tion of an elongated substantially horizontal heat ing chamber, an endless conveyor extending through said chamber, means associated: with said conveyor adapted to support the work bars on edge in a substantially upright position and convey the same through said heating chamber, a combustion chamber along one side of said heating chamber, and a longitudinally extending partial partition between said combustion chamber and said heating chamber, sa d partition provided with longitudinally spaced transversely extending ports adjacent its bottom edge adapted to project burning gases transversely through the spaces between adjacent work bars as the same are being carried through the furnace.

2. In a continuous pair furnace, the combination of an elongated heating chamber, an;- endless conveyor extending thrcugh said chamber, means associated with said conveyor adapted to support the work bars on edge and convey the same. through said heating chamber, a combustion chamber along one side of said heating chamber, and a longitudinally extending partial partition between said combustion chamber and said heat-a ing chamber, said partition provided with longi tudinally spaced transversely extending ports adjacent its bottom edge adapted to project burn= ing gases transversely through the spaces be tween adjacent work bars as the same are being carried through the furnace, and along its upper edge being stepped down towards the source: of fuel introduced to said combustion chamber for at least a part of its length.

3. In a continuous pair furnace, the combination of an elongated heating chamber, an endlesss conveyor extending through said chamber, means associated with said conveyor adapted to support the work bars on edge and convey the samethrough said heating chamber, a combustion chamber along one side of said heating chamber, and a longitudinally extending partial partition between said combustion chamber and said heating chamber, said partition provided with lon gitudinally spaced transversely extending ports adjacent its bottom edge adapted to project burning gases transversely through the spaces between adjacent work bars as the same are being carried through the furnace, and along its upper edge being stepped down towards the source of fuel introduced to said combustion chamber for at least a part of its length, and provided with lon gitudinally spaced vertically arranged bafiles throughout the remainder of its length.

4. In a continuous pair furnace, the combination of an elongated heating chamber, an endless conveyor extending through said chamber for carrying work bars in a substantially upright transverse position therethrough, means for projecting burning gases into said heating chamber, a substantially curved hood arranged to extend forwardly and downwardly from said heating chamber over the charging opening of said heating chamber, and a flue associated with said hood adapted to draw off at least a portion of said gases, said bars in transverse position cooperating with said curved hood to act as a closure for said chamber.

5. In a continuous pair furnace, the combination of an elongated heating chamber, an endless conveyor extending through said chamber for carrying work bars in a substantially upright transverse position therethrough, means for projecting burning gases into said heating chamber, a substantially curved hood arranged to extend rearwardly and downwardly from said heating chamber over the discharge opening of said heating chamber, and a flue associated with said hood adapted to draw off at least a portion of said gases, said bars in transverse position cooperating with said curved hood to act as a closure for said chamber.

6. In a continuous pair furnace, the combination of an elongated heating chamber, an endless conveyor extending through said chamber for carrying work bars in a substantially upright transverse position therethrough, means for projecting burning gases into said heating chamber, substantially curved hoods respectively arranged to extend from said heating chamber forwardly over the charging and rearwardly over the discharge openings of said heating chamber, and flucs respectively associated with said hoods each adapted to draw off at least a portion of said gases, said bars in transverse positions cooperating with said hoods to act as closures at the charging and discharging ends of said chamber.

'7. In a continuous pair furnace, the combination of an elongated heating chamber, an endless conveyor extending through said chamber and trained about a sprocket adjacent the discharge end of said chamber, a plurality of brackets secured to said conveyor in spaced relation for carrying work bars through said heating chamber, and discharge skids for the work bars leading out of said chamber from adjacent said sprocket, and terminating immediately adjacent said discharge end, said brackets secured to said conveyor in such spaced relation relative to the radius of said sprocket that a particular bracket may discharge its work bars onto said skids while the next succeeding bracket still supports its work bars in a substantially vertical slightly inclined position in said heating chamber, whereby said bars after assuming a forwardly inclined position are free to slide down said skids.

8. In a continuous pair furnace, the combination of an elongated heating chamber, an endless conveyor extending through said chamber and trained about a sprocket adjacent the discharge end of said chamber, a plurality of brackets secured to said conveyor in spaced relation for carrying work bars through said heating chamber, and discharge skids for the work bars leading out of said chamber from adjacent said sprocket, and terminating immediately adjacent said discharge end, said brackets secured to said conveyor in such spaced relation relative to the radius of said sprocket that a particular bracket may discharge its work bars onto said skids after the next preceding bracket has dropped beneath the work supporting surface of said skids and while the next succeeding bracket still supports its work bars in a substantially vertical slightly inclined position in said heating chamber, whereby said bars after assuming a forwardly inclined position are free to slide down said skids.

9. In a continuous pair furnace, the combination of an elongated heating chamber, an endless conveyor extending through said chamber and trained about a sprocket adjacent the discharge end of said chamber, a plurality of brackets secured to said conveyor in spaced relation for carrying Work bars through said heating chamber, said brackets provided with different height projections respectively arranged at opposite sides thereof and adapted to support work bars in a substantially vertical position therebetween as said conveyor moves through said heating chamber, and discharge skids for the work bars lead ing out of said chamber from adjacent said sprocket, and terminating immediately adjacent said discharge end said brackets adapted to move downwardly in an arcuate path past said skids and in so moving carry the shorter of said projections below the work supporting surface of said skids in advance of the longer of said projections to thereby discharge the work bars onto said skids, where such bars are free to slide down such skids.

10. In a continuous pair furnace, the combination of an elongated heating chamber, means for carrying work bars through said chamber, means for projecting burning gases into said chamber, an arch extending over one opening into said chamber, a metallic hood forming a substantial part of said arch for draining off at least a portion of the gases from the heating chamber, and a flue associated with said hood.

11. In a continuous pair furnace, the combination of an elongated heating chamber, means for carrying work bars through said chamber, means for projecting burning gases into said chamber, an arch extending over one opening into said chamber, a metallic hood forming a substantial part of said arch for draining off at least a portion of the gases from the heating chamber, and a flue associated with said hood, said hood and at least a portion of said flue removable as a unit from said arc.

12. In a continuous pair furnace, the combination of an elongated heating chamber, a flue at the discharge end thereof, a sprocket wheel mounted at said end, an endless conveyor extending through said chamber and passing about said sprocket wheel, an unloading skid so mounted that its runway receives work bars discharged by gravity from said conveyor, and transfers said Work bars from within the heating chamber to a cool zone adjacent the discharge opening thereof, bracket members adapted to support on edge and carry work bars and mounted on said conveyor in such spaced relation relative to the radius of their path about the said sprocket wheel, that, as a bracket member discharges work bars down said skid the next bracket member forward will be below the level of the runway of said skid, and the position of said flue relative to said sprocket wheel being such that as work bars are discharged from a bracket member the next bracket member following is within the heating zone of said chamber.

13. In a continuous pair furnace, the combination of an elongated chamber, a flue at the discharge end thereof, a wheel mounted at said end, an endless conveyor extending through said chamber and passing about said wheel, bracket members mounted on said conveyor in spaced relation and adapted to support on edge and carry Work bars; the spacing of said bracket members and the location of said flue relative to said wheel being such, that, as work bars are discharged by gravity from a bracket member, to a zone beyond the heating zone the next following bracket member will be in the zone of gas flow through said chamber, and means to advance said conveyor.

14. In a continuous pair furnace, the combination of an elongated heating chamber, a combustion compartment laterally thereof and communicating therewith, a flue at the discharge end of said chamber, an endless conveyor extending through said chamber and brackets carried by said conveyor adapted to support work bars on edge and carry same through said chambers, said flue being so located that the discharge end of the flat portion of the upper run of said conveyor is within the zone of gas flow through said chamber, and skid means cooperating with the discharge end of said conveyor to transfer said work bars out of the heating zone.

15. In a continuous pair furnace, the combination of an elongated heating chamber, an endless conveyor extending through said chamber, brackets mounted in said conveyor and adapted to support work bars on edge and convey same through said heating chamber, a combustion chamber extending along one side of said heating chamber and in communication therewith with a partial partition therebetween, and a flue at the discharge end of said heating chamber so placed that the discharge end of the upper run 1 of said conveyor is positioned in the path of gas flow in said heating chamber, and skid means 00- operating with the discharge end of said conveyor to transfer said work bars out of the heating zone.

16. In a continuous pair furnace, the combination of an elongated heating chamber, an endless conveyor extending through said chamber, means associated with said conveyor adapted to support the work bars on edge and convey same through said heating chamber, skid means for transferring said Work bars out of the heating zone, combustion chambers arranged laterally adjacent said heating chamber at opposite ends and respectively at opposite sides thereof, partial partitions between said combustion chamber and said heating chamber, hoods extending outwardly and downwardly over the charging and discharging openings of said chamber, and flues respectively associated with said hood and adapted to withdraw therethrough burning gases from the heating chamber, and so direct the flow of such gases that they sweep over the entire area of said conveyor which normally carries work bars.

, RAY M. FENTON. 

